Contents

History

For the 2001 model year Honda released an upgraded version of the popular CBR600F4 with intentions of becoming more competitive in the middleweight sport bike class. The 370 pound F4i is a modified F4 with numerous engine, chassis and bodywork changes.

The single largest change, other than the styling, is the addition of high-pressure (50 psi) programmed fuel injection - thus the model designation "F4i". Fuel injection allows for more precise fuel metering and delivery over a wider rpm range, while providing better throttle response and decreasing emissions. The injectors reside one per cylinder and work with 38 mm throttle bodies. Each injector has four nozzles, and together the injectors add up to five horsepower over the F4. The wheelbase is five millimeters shorter than its predescessor, with a 5.9-percent increase in overall rigidity.

Weight was also been reduced. The rear wheel was made 400 grams lighter, the cush drive 600 grams, and the front wheel 300 grams. The wheel bearings has been moved outward, closer to the fork tubes and the rotor carriers moved out closer to the brake calipers - all to reduce weight and to improve rigidity. Each caliper carrier also lost 100 grams. There's additional bracing on the steering head for more response, better feedback and feel from the front end. The suspension has also been tweaked with less high-speed damping and a little more low-speed damping.

Additional engine changes include a lighter cam-shaft sprocket and increased valve spring pressure (two springs per intake valve) which allow for higher revving. There are new piston rings that slide with less friction and increased internal engine oil flow. Redline is now 14,200 rpm, 700 rpm higher than the previous year's F4. To increase the bike's pulling capabilities at high speeds, 5th and 6th gears have been shortened slightly and the rear sprocket was enlarged from 45 teeth to 46. The oiling holes in the camshafts have been enlarged by 0.5 mm (to 2.5 mm) and piston ring friction has been decreased to aid cooling at the higher rev ceiling. Spring pressures on the intake and exhaust valves have been increased to avoid valve float. Also, there are now two valve springs (inner and outer) on the intake side instead of the single item that resides on the exhaust side.

In 2003, Honda introduced the CBR600RR, a higher-performance race-ready middleweight to succeed the F4i. The F4i remained available for three more years until its demise after the 2006 model year. In 2006 the Honda CBR600F4i retailed for US$8,499. No major updates were made in these final years except for color scheme changes.

Styling

Honda included some styling changes due to criticisms of the F4 being too bland. The 2001 F4i features a new subframe which raises the seat by five milimeters and an improved two-tier seat allows for more storage room in the rear compartment. The new tail unit has a less padding and a higher perch for the passenger. The F4i’s tail-light is smaller with a new dual-bulb configuration. The F4i features a new dash layout with a large analog tachometer. The new LCD digital display includes a speedometer, odometer, clock, engine temperature read-out, amber shift indicator, and trip meters.

The F4i's new bodywork carries a more 'racy' look and provides a 3% reduction in drag. It also houses a new dual headlight front cowl design which uses 40% brighter H7 bulbs compared to the old H4 bulbs. The headlights are dual multi-reflector units covered by a one-piece flexiglass lens. The turn stalks are shorter and the mirrors are now positioned higher and closer to the rider. The elimination of carburetors allowed for a slightly larger air box and a larger fuel tank (4.8 us gallons / incl. 0.9 reserve) complete with a delayed fuel level sensor to prevent false readings when the bike is at an angle.

In 2004 Honda replaced the black frame with one in silver and a banana seat to differentiate the F4i from the 600RR. A one piece seat was also added due to complaints of comfort.